Based on theoretical analysis, this paper proves that the use of irregular 19 groups of frequency reuse scheme can be used to raise the spectrum efficiency of mobile communication networks.

TD-SCDMA is characterized by outstanding benefits such as high spectrum efficiency, high system capacity, low facility and network building costs, global roaming, best asymmetrical data service support, and acceptable terminal mobility, all of which comply with ITU requirements.

To improve the spectrum efficiency has been an important issue to wireless communication recently.

A novel ultra-wideband (UWB) pulse design algorithm combining the methods of spectrum analysis and orthogonal basis synthesis in time domain is presented to improve the spectrum utilization efficiency and conform the federal communications commission (FCC) emission mask constraint.

The pulse designed here not only was limited to time so as to reduce the multiple access interference but enhanced the spectrum utilization efficiency under the spectral mask constraint,which improved the transmission quality of a UWB system.

The simulation results indicate that collaborative spectrum sensing can improve the spectrum sensing performance significantly,combat the shadowing or fading effects and enhance the spectrum utilization efficiency.

The computer simulations demonstrate phase continuous QAM can successfully raise frequency using ratio.

The cross-layer design in combining of adaptive modulation and coding with truncated ARQ is now extensively adopted to enhance data rate in wireless communication systems,which increases spectral efficiency greatly.

System simulation shows that the proposed strategy can achieve higher system throughput and spectrum utilization than two existing uniform power allocation schemes.